1. Field of the Invention
The invention relates to a transmission control for a motor vehicle wherein the load acting on the motor vehicle is taken into consideration when determining the point for shifting gears.
During steady driving, i.e. when neither accelerating nor decelerating, this load contains a constant portion based on the resistance to movement (air resistance and friction of rotation) and a changing portion, depending on the upslope or incline of the road.
2. Description of the Related Art
In a known device for the determination of the upslope of the road (disclosed in European Patent No. 0 142 633 B1), the measured values provided by sensors for engine rpm, number of wheel revolutions, position of the gas pedal, etc. are evaluated and the drive torque or rpm torque portions required for overcoming the load portions mentioned above are computed. Other known control configurations for automatic transmissions also displace the shift points of the transmission as a function of drive parameters, in particular of the upslope of the road, actually in accordance with varying computing commands (as disclosed in German Patents DE 28 52 195 C2 and DE 30 18 033 C2).
A device for controlling a clutch-transmission unit adapts itself to the driving habits of the driver and to the prevailing driving or traffic situation (as disclosed in German Patent DE 33 41 652 C2). In order to accomplish that objective, the device receives a plurality of various measurement signals and evaluates them in a complicated way for operating a run-off control.